Method of and mechanism for tying knots



Oct; 27, 1942. H. cs. LlND METHOD OF AND MECHANISMS FOR TYING KNOTSFiled June 7, 1939 4 Sheets-Sheet l INVENTOR Harry Lind Oct. 27, 1942.H. s. LIND METHOD OF AND MECHANISMS FOR TYING KNOTS Filed June '7, 19594,Sheets-Sheet 2 |NVENTOR 7 Ha rry G. L (Ln 0? BY m m J r ATTORNEYS Oct.27, 1942. H. e. LlND 2,300,051

METHOD OF AND MECHANISMS FOR TYING KNOTS I Filed June '7, 1939 4Sheets-Sheet 5 INVENTOR Harry G L ind ATTORNEY 5 Oct. 27, 1942. H. G.LIND METHOD OF AND MECHANISMS FOR TYING KNOTS Filed June '7, 1939 4Sheets-Sheet 4 m 0 aw G. Lind ATTORNEYS INVENTOR TE toNE E M FWQK @NkkElk Patented Oct. 27, 1942 Harry G. Lind, Rockford, 111., assignmtoBarber- Colman Company, Rockford, 111., a corporation of Illinois Apflication June 7, 1939, Serial No. 277,755

20 Claims.

The invention relates to an improved method of and apparatus for tyingknots, and more particularly, for uniting threads or strands of suchmaterial as woolen yarn.

in some aspects the present invention may be considered as animprovement upon the knot-tying method and apparatus disclosed in BurtA. Peterson Patent No. 1,657,407 issued January 24, 1928 in which apairof threads are united by a so-called weavers knot.

A weavers knot has been found to be well adapted to the permanentuniting of the ends of cotton threads or yarn. In the case ofwool,however, a weavers knot is likely to become untied, and it is thereforethe general object of the present invention to provide a method of andmechanism for tying knots which, while not limited to use with woolenyarns, is capable of firmly and permanently uniting yarns of suchmaterial.

More specifically, it is an object of the invention to provide a methodof and mechanism for tying together a pair of threads by means of anovel form of knot, which is somewhat related in form to a weavers knot,but which embodies variations in the configuration and relativepositions of the threads such that the threads are firmly interlockedand held together even though made of such materials as wool.

Further objects and advantages of the invention will become apparent asthe following description proceeds, taken in connection with theaccompanying drawings in which:

Figure 1 shows a completed knot of novel form made in accordance withthe improved method of knot tying herein disclosed.

Fig. 1 shows the loop formation of the threads before the knot of Fig. lis drawn tight and completed.

Fig. 1 shows the configuration of the threads intermediate the steps ofFigs. 1 and 1, respectively. i

Fig. 2 is a side elevation of a knotter mechanism embodying theinvention. Parts moving to the right in this view are hereinafterreferred to as moving outward1y."

'Figs. 3 and 4 are, respectively, enlarged detail end and plan views(partly in section along the lines 33 and 4l, respectively, in Figs. 2and 3) of the mechanismjor actuating the knotter post.

Fig. 5 is an enlarged detail bottom plan view of one of the threadclamps of the knotter mechanism.

Figs. 5, 5 and .5 are stop motion views similar to Fig. 5 showingsuccessive steps in the operatio of the parts illustrated. I

Fig. 6 is a fragmentary detail view of part of the mechanism of Fig. 5.

Fig. 7 is an enlarged detail perspective view of the slack take-upmechanism included in the knotter.

Figs. 8 to 12, inclusive, are fragmentary perspective views of theknotter mechanism showin successive steps'in the knot tying operation.

Fig. 13 is a time chart illustrating the sequence of operations of thevarious mechanisms by the controlling cam.

Referring more particularly to the drawings, Fig. 1 shows a completedknot uniting a pair of threads at and b. For purposes of exemplifica-'tion only, it will be assumed that thread a is a reserve thread leadingfrom a bobbin in a windin machine and that thread b is an exhaustedthread on a cheese or yarn mass which is being wound in the machine. Tomake more readily discernible the convolutions of the two threads a andb, these threads have been shown in the drawings as white and black,respectively. The knot of Fig. 1 is of novel form and has been foundcapable of firmly and permanently uniting woolen threads. It is referredto herein as a doubly interlocked knot.

To better understand the configuration of the threads a and b in thedoubly interlocked knot of Fig. 1, reference should be made to Fig. 1 Inthis figure the threads are shown before they are finally drawn tight tocomplete the knot. In Fig. 1, the threads 11 and b are looped in what,for purposes of explanation and analysis, may conveniently be termed amodification of a loose weavers knot. A weavers knot as such is, ofcourse, a well recognized standard knot, and as to it, reference may bemade, for example, to Fig. 29 of said Peterson patent referred to above.

Upon a comparison of a weavers knot with that of Fig. 1 herein it willbe seen that the two are alike in that, first, there are oppositelyextending loops or and D1 in the end portions of the respective threads0 and b, second, the standing part oz, of one thread 0, extends throughthe loop in in the other thread b, and third, the standing part b2 andend b: of the other thread b extend side by side through the loop at inthe first thread a. The knot of Fig. l diifersfrom a standard weaversknot, however, in that the end a: of the first thread a is'not clampedbetween the standing part of the thread a and the oposed portions of thestanding part be and end be of the other thread b, but is, on the otherhand, twisted about the standing part as of the thread a and thrustoutwardly from the remainder of the stands. By virtue of this difierencein configuration of the strands it is possible finally to draw the knottight in a manner which will hereinafter appear, so as to form thestrong and durable doubly interlocked knot of Fig. 1.

In accordance with one aspect of the present invention the threads to beunited are preliminarily looped in a somewhat loose form with thestrands arranged as shown in Fig. 1 in what is termed herein a modifiedform of Weaver's knot. Then, to complete the novel knot of Fig. 1, thetwisted portion of one of the threads (shown in Fig. 1 at in) is pulledthrough the loop of the other thread (shown as bi) as an incident todrawing the knot tight (Fig. 1 In this wayv the loop bl, in the threadb, encircles and firmly clamps the twisted portion 04, of the thread .a,against the standing part a: of the thread a. In general, the strandsare so interwoven or interlocked that an extremely strong and firm knotis formed even though the strands or threads be made of wool.

In carrying out the present invention the preliminary looping of thetherads in the form of a modified Weaver's knot such, for example, asthat shown in Fig. 1, is preferably accomplished by means of a novelmethod of knot tying herein disclosed. Generally stated, this methodcomprises (see' Figs. 8 to 12), seizing a bight in one of the threads(such as the thread a) to form a main loop. The loop is then made intowhat may be termed a "doubly twisted loop by twisting the thread at thebase of the loop about itself through substantially a turn and a. halfat the base of the loop (see Fig. 8). Then a bight of the same thread,adjacent the main loop is drawn through the loop to form a temporarysecond loop. Thereupon a second thread (such as the thread b) isinserted through the second loop thus formed, and the second loopsubsequently withdrawn from the main loop, together with the insertedthread, thereby forming a third loop encircling one of the standingparts of the thread having the main loop in it. In the course of thiswithdrawal operation the second or temporary loop is dissolved. Bymanipulatin the threads in this manner the formation of the initial mainloop forms, for example, the final loop cu in the thread a and leavesthis thread twisted at the base of the loop as shown at or. similarly,the third loop, so-called above, 'is represented in Fig. 1 by the loop bin the second thread b. Having thus preliminarily arranged the threadsas shown in Fig. 1, they may then be pulled tight into the form of Fig.1 and then Fig. 1, as previously described The novel knotter mechanismherein disclosed, for carrying out the knotting method outlined above,is basically similar to that disclosed in said Peterson patent.Accordingly, reference may be had to such patent for a generaldescription of the apparatus and for details of parts which aresubstantially identical. The more detailed portions of the descriptionherein are directed primarily to the difierences in construction whichmake possible the use of the knotter herein disclosed for tying thenovel form of doubly interlocked knot of Fig. 1, as distinguished froman ordinary weavers knot such as is tied by the knotter of said Petersonpatent.

Referring now to Fig. 2, the present embodiment of the knotter mechanismis adapted to receive a pair of threads (not shown in Fig. 2) at itsouter end for tying them together. For example, one of the threads maybe a reserve thread, that is, one from a reserve bobbin, and the otheran exhausted thread end from a cheese or yarn mass in a winding machine.For an example of a winding machine of the type referred to, Howard D,Colman Patent No. 1,267,977 may be considered. 0f the two threads noted,the reserve thread is operated upon first in the present mechanism and,consequently, the manipulations of this thread will be first described.

The reserve thread is seized at two vertically spaced points, to form abight between them, by the suction nozzle 9 and a lower clamp ll (Fig.'2), the loose end of this reserve thread being picked up by the nozzle.After the threa has been looped it is seized and sheared oil by an upperclamp I 0, the waste end of the thread being drawn ofi in the suctiontube. The upper clamp may be substantially identical with thecorresponding clamp in the knotter of said Peterson patent. Theactuating mechanism for the lower clamp H is, however, of somewhatdifferent form than that of the Peterson knotter in view of thediflerent timing required in the present knotter. Furthermore a slackdrawing hook l2, located just above the lower clamp II, is in thepresent device arranged to aid in actuating such lower clamp and iscombined with other parts in a novel form of tensioning mechanism toexert a tension on the reserve thread, which varies in value atdifferent periods in the knotting operation to match the requirements ofthe operations used in tying the novel knot herein contemplated.Consequently the lower clamp ll, slack drawing hook I2 and associatedthread tensioning parts are described hereinafter in some detail in viewof the novel structures involved. In the case of the upper clamp l0 andother such parts which are substantially duplicated from those shown insaid Peterson patent, reference may be made to the latter for details ofconstruction.

Generally stated, the upper clamp 10 is a shearing and gripping clamp.It not only grips the end of the thread, but also shears it off neatlyadjacent the knot. The lower clamp H is, however, simply a gripping,rather than a combined shearing and gripping, clamp. These clamps areactuated in timed relation to each other and to the other parts of theknotter (see time chart Fig. 13). Moreparticularly, at least one andpreferably both clamps remain open until the initial looping of thethread has been accomplished (see Fig. 8) in the knotting operation sothat suflflcient slack will be available for this purpose. During thistime the thread is tensioned sufficiently, to stay in place, by theslack drawing hook l2. This hook not only serves to tension the threadbut also draws a little additional slack which is'released for knottingpurposes after the clamps Ill and H are closed.

Of primary importance in carrying out the knotting operation is themaintenance of the threads in proper position and under requisitetension. The clamps serve to position the threads for this purpose andthe slack hook I2, with its cooperating parts hereinafter described,adjusts the tension in the reserve thread automatically to suit therequirements of successive steps in the knotting operation.

To insure proper timing of the various actuating elements of the knottermechanism they are all driven from a single rotatable cylindrical cam l3(Figs. 3 and 4). This cam has suitably contoured individual cam tracksin both its end and side surfaces. The relative timing of the actuationof the different parts may be determined by reference to the time chart,Fig. 13.

The lower clamp II for the reserve thread (Fig. embodies a fixed jaw orfinger I34 and a cooperating movable Jaw or clamping finger IS. The JawI4 is shown herein as an integral extension on a stationary plate It(see Fig. 2 in addition to Fig. 5). Similarly, the movable jaw l5constitutes an integral extension on a plate II, which is pivoted on astud l8 riveted. to the stationary plate l6 and is yieldably urgedagainst the bottom face of the latter by a. compression spring I!encircling the stud l8.

As to the actuation of the lower clamp II for the reserve thread,initial movement of the swingable clamp jaw l5 from open position (Fig.5) to an intermediate position in which it is"just ready to close (Fig.5-) is accomplished in response to a retractive motio of the slackdrawing hook i2. In this retrac ive or inward motion of the hook I2,slack is p lled in the bight of the reserve thread lying between theclamps I0 and H so that suilicieni; thread will be available for formingthe doubly twisted loop in the knotting operation.

The slack hook I2 is fashioned onthe end of an arm 20, pivotedintermediate its ends at 2| and having a cam follower roller (not shown)on its inner end which is received in a cam track groove on theactuating cam l3. As the slack hook I2 is retracted it pulls a bight ofthe reserve thread a across a projection 23 (Fig. 7) on a plate 24located at the upper surface of the slack hook. Furthermore, during thisretraction of the slack hook I2 a cam plate 25 bolted to the hook arm 20strikes a pin 26. This pin 23 is carriedby a curved link 21, pivoted atits upper end, and passes through a cam slot 28 in the movable clamp jawplate l1. Accordingly, as the hook arm 20 continues its descent to theposition of Fig. 5, the pin 28 rides along a cam surface 29 on the camplate 25 and oscillates the clamp plate I! from its full open position(Fig. 5) to its intermediate but still open position (Fig. 5*). In thisway the movable clamp jaw II is shifted to an intermediate point orposition where it is Just ready to close during the time that the slackis being drawn for the knot by the slack hook l2.' It will be noted thatthe pin 24 has a flattened side 26' (Fig. 6) opposed to the cam plateedge 23.

Final closure of the lower clamp II is accomplished in response to alateral shifting of a vertical knotter post 30 (see Fig. 2 as well asFig. 5) which takes part in the knotting operation. This knotter post isboth laterally and axially movable, being substantially identical inform and function with the corresponding part in said Peterson patentnoted above. that the post 30 is carried on and shifted laterally by apivoted arm 3| which is oscillated by the main driving cam l3. Toachieve this final closure of the clamp I I in response to the movementof the knotted post 30, a stud 3| on the arm 3| which also carries thepost 30 is utilized as a pivot for the link 21. Consequently, when theknotter post 30 is shifted laterally (upward as viewed in Fig. 5) by thecorresponding movement of its supporting arm 3|, the stud 3| pulls up onthe link 21 and drags the pin 23 about the nose of the cam plate 25(Fig. 6). The shift of the post 30 to close the clamp carries the postfrom the position of Fig. 5 to that of Fig. 5'. By thus shifting the pin26 to the right (as viewed in Fig. 5) the clamp jaw plate I! isoscillated to It may be noted here its fully closed position (Fig. 5').By virtue of this timing the reserve threada can be freely drawn throughthe lower clamp l l during the initial looping of the thread in theknotting operation, and in this interval the slack hook I2 is retractedto tension the thread and to draw slack in the bight of the thread.Aftegr this slack is drawn the lower clamp I i is closed to hold thelower end of the bight firmly. Y

For the first step of the looping of reserve thread a in the actualknotting operation, a knotter hook 32 (Figs 2 and 8) is retractedaxially inward (to the left as viewed in Fig. 8) and is simultaneouslyrotated in a counte clockwise direction, through substantially a full umand a half. In the course of this retractive ovement the hook 32 engagesthe bight of t e reserve thread a and the rotation of the hook twiststhe thread so as to form the main loop or for the final knot with thetwisted portion atiat the base of this loop, which is utilized inobtaining the subsequent configuration of the threads as shown in Fig.1' described above. The end as of the reserve thread is gripped by theupper shear clamp I!) while the standing part or of this thread passesover a vertically shiftable finger 33 and through the lower clamp H. Theupper clamp i0 is timed to close at the end of this retractive androtative movement of the hook 32 while the lower clamp i I closes justslightly later (see time chart, Fig. 13). Consequently, ample slack isavailable for the looping and twisting of the thread by the hook 32during the hook movement just described.

Before proceeding to the next step in the knotting operation, attentionmay be given to the actuating mechanism for the knotter hook 32 (Figs.2, 3 and 4) In this particular arrangement, the hook 32 is carried onthe outer end of a rotatable and axially shiftable shaft 34, which issuitably journaled in the frame of the mechanism. Axial shifting of theshaft 34 is effected bymeans of an oscillatable lever 35 (Fig. 4)pivoted intermediate its ends at 36 and having a cam follower roller 31on its inner end which rides in a cooperating cam groove in one end faceof the actuating cam l3. A segment of teeth 38 on the opposite end ofthe lever 35 mesh with teeth 39 on the shaft 34, which may beconveniently spirally formed. Thus, as the lever 35 is oscillated by therotation of the actuating cam I3, the knotter hook shaft 34 will beshifted axially in proper timed relation to the actuation of the otherparts of the mechanism. Similarly, rotative movement of the hook shaft34 is accomplished by means of a lever 40 (Fig. 3) pivoted intermediateits ends at 4| and having a cam follower roller 42 on one end thereofwhich is received in a complemental cam track groove in the side face ofthe actuating cam 13. For the sake of compactness it is desirable toaccomplish the necessary rotation of the hook shaft 34 through its fullturn and 'a half with a minimum of throw for the lever 40 andconsequently a motion multiplication connection is provided between thelever 40 and the shaft 34. This connection includes a segmental seriesof teeth 43 on the free end of the lever 40 which mesh with a pinion 44.Fast on this pinion. 44 is a segment of teeth 45 of larger radius thanthe pinion and which in turn mesh with an elongated pinion 4i fixed onthe shaft 34. In this way rotation of the knotter hook 32 on the end ofthe shaft 34 is also effected in timed relation of the actuation of theother knotter mechanism elements.

In the second principal step of the knotting operation the knotter book32 is utilized to form a temporary loop in one of the strands formingthe main loop or in the reserve thread a. and to draw this temporary orsecond loop through the main loop. To pull the loop a, over to the sideof the shank of the hook 82 opposite the point of the hook, the knotterpost or pin 30 is shifted laterally toward the reserve thread a from theposition of Fig. 8 to that of Fig. 9.' The initial portion of thislateral shift of the knotter post It serves to finally close the lowerclamp I I, as was previously described. During the lateral shift of theknotter post Ill just described, the slack hook I2 is moved outwardlyslightly to provide sufiicient slack in the thread as it is pushedtransversely by the knotter post (see time chart Fig. 13)

After the knotter post 20 has been shifted a sufiicient distance toclear the knotter hook 22, the latter is projected outwardly to theposition of Fig. 9 so that the main loop in rides up on the shank of thehook. Furthermore, during the advancing movement of the hook 32 thefinger 33 is elevated from its position shown in Fig. 8 to the dot-dashline position shown in Fig. 9 and then quickly dropped again to the fullline position shown in Fig. 9. In this way the standing part a: of thethread a is dropped over the end of the hook 22. Thereafter the hook 32is rotated in a clockwise direction through substantially 180, or a halfturn, so that its nose can pass through the main loop in (Fig. 10).Finally, the knotter hook 32 is withdrawn to the position of Fig. 11,thereby drawing a second or temporary loop as through the main loop m.It should also be noted that in the course of this retractive movementof the hook 32 that it is re-rotated through substantially 180 in acounterclockwise direction so that the strands making up the loop aswill not be crossed.

At this point in the knotting operation (Fig. 11) the reserve thread ais looped in what is in efiect a loose bowknot except that the strandsof the main loop in of the knot are twisted through a full turn and ahalf rather than merely through a half turn as in a conventionalbowknot. The temporary loop as constitutes, of course, the bow of thebowknot. I

Insertion of the second or exhausted thread b into the temporary secondloop as in the reserve thread it, constitutes the third main step of theknotting operation. For this purpose an ex-' hausted thread hook 41 isprojected laterally through the temporary loop as to the dot-dash lineposition shown in Fig. 11 in which it engages a bight in the exhaustedthread b which is presented to the knotter at the proper time by adow'n-take arm (not shown) like that of said Peterson patent. Thereuponthe hook I! is retracted and draws with it a bight of the exhaustedthread 6 through the loop as. This bight of the exhausted thread b isgripped between the hook 41 and a cooperating shearing clamp plate orjaw ll so that the exhausted thread is sheared off at this point andheld with the thread extending through the temporary loop an in thereserve thread (Fig. 11)

In the fourth main step of the knotting operation, the temporary loop inthe reserve thread is pulled back through the main loop or so as todissolve this temporary loop and at the same time draw the reservethread b through the main loop (:1 and leave the exhausted thread loopextending about the standing part a: of the re-' serve thread. To thisend, the knotter hook 32 is thrust outwardly again past the post 30 soas to free the temporary loop as from it, and coincidentally tension isapplied to the standing part a: of the reserve thread by the slacktake-up hook i2. This amounts, of course, to applying tension to therunning strand of the bow for the temporary bowknot described above. Inthis way. the standing part a: of the reserve thread is drawn backthrough the main loop 01 bringing with it the exhausted thread I: sothat the threads occupy substantially the configuration shown in Fig.12. Upon reference to this latter figure, it will be seen that thethreads have now been looped in a modified form of loose weavers knotsubstantially like that of Fig. 1. The ends a; and ha of the reserve andexhausted threads are clamped as is the standing part b: of theexhausted thread. The standing part a: of the reserve thread a is alsoclamped and in addition tension is being applied to it by the slack knotl2 which has a further retractive movement at this point (see time chartFig. 13)

Inthe fifth and final step of the knotting operation, the loops formingthe knot are drawn tight and as an incident to such tightening of theknot the twisted portion at of the reserve thread is drawn through theloop in in the exhausted thread so that in the completed knot thethreads will have the configuration of the novel doubly interlocked knotshown in Fig. 1. For this purpose the tension onthe standing part a: ofthe reserve thread is continued while the knotter post 30 is shiftedaxially downward to slip it free from the knot. It should be noted thatthis step of drawing a twisted portion of one thread within a loopin-the other is wholly novel and finds no counterpart in theconventlonal weavers knot.

Opening of the clamps I0 and Ii releases the reserve thread a at thecompletion of the knotting operation described above. The upper clamp I0is actuated directly from the cam i3, just as in the case of thecorresponding clamp in said Peterson patent heretofore noted, and isopened at the end of the described knotting operation by an actuatingarm which is shifted by the cam I 3. The lower clamp Ii, however, isopened, in the present case. by a further and extreme lateral shift ofthe knotter post 30 to the position of Fig. 5. In the course of suchlateral movement of the post 30 the link 21 is pulled upwardly (asviewed in Fig. 5") and the pin 26 rides along the outer end face of thecam plate 25. As a result, the pin 26 oscillates the clamp plate IT in aclockwise direction (as viewed in Fig. 5') so that the clamp finger I 5,on the plate I 1, is swung to its full open position (Fig. 5). when theknotter post SI comes to rest in its extreme laterally shifted positionthe pin 2 is seated in t e upper end of the slot 28, with the clampplate I! and link 21 in the positions of Fig. 5. The arrangement of theparts issuch that the clamp II will remain open during the time that t earm 20, which carries the cam plate 25 and slack hook l2, returns to itsinitial position (Fig. 5). As the arm 20 rises, the curved outer endface of the cam plate 25 rides past the pin 26 without changing thelatters position. Similarly, upon the subsequent descent or returnlateral movement of the knotter post 30, the pin 26 rides down thegroove 28 and without shifting the angular position of the clamp plateI! about its pivot pin IS. The friction of the compression spring is,which encircles the pin i8, is sufiicient to overcome the friction ofthe pin 26 in the slot 2l,'during the descent of the pin 28 just noted,so that the position. As a result the parts all finally return to theirinitial positions shown in Fig. 5. In this same connection it will benoted that at a much earlier point in the cycle (see the time chart,.

Fig. 13) the clamp II also remains closed even though the knoter post 34is returned from its intermediate position (shown in Fig. to its initialposition (shown in Fig. 5). The clamp plate i1 remains immobile duringthis intermediate return motion or the knotter post 30 since the pin 25rides down the slot 28 and again the spring It prevents angular movementor the clamp plate ll which would otherwise be caused by the friction ofthe pin 25 on the edges of the slot 25.

A diflerence in the tension placed on the reserve thread a, by the slackdrawing hook I2, is desirable in difierent portions of the knottingoperation. In particular, during the initial drawback of the knotterhook 32 the thread is in a position to 'withstand a substantial tensionexerted by this knotter hook and the tensioning hook l2. Near the end ofthe knotting operation, however, when the hook I2 is retracted stillfurther, to complete the drawing tight or the knot, the thread is notpositioned to withstand tensioning so well. Accordingly, means has beenprovided in which two springs, or similar yieldable biasing members, arearranged so that slack is drawn against the resistance oi! both of thesesprings during the first .period mentioned and against the resistance oronly one spring during the second period.

In the particular thread tensioning construction illustrated (Fig. '7),the plate 24 is pivoted on a pin 49 carried by a bracket 50. As theslack hook |2 descends it draws the reserve thread a across theprojection 23 on the plate 24 so that the latter tends to swing in acounterclockwise direction (as viewed in Fig. 7). Swinging oi the plate24 in this direction is yieldably resisted by a pair of contractilesprings 5| and 52. The spring 5| is anchored at its outer end to aprojection 53 on a fixed plate 54, which carries the bracket '55.Similarly, the inner end of the spring 5| is anchored to an arm 55integral with the plate 24. It should be noted at this point that thearm 55 is notched as indicated at 55 so that the point of attachment forthe spring 5| may be varied at will with a consequent change in thelength of the moment arm about the pivot pin 49 through which the springacts and, hence, a corresponding change in the biasing, torque exertedby the spring on the plate 24.

The second biasing spring42 has an indirect connection with theswingable plate 24 so that it is operatively connected thereto duringonly a portion of the period occupied by the complete knot tyingoperation. In particular, the outer end of the spring 52 is anchored tothe fixed plate 54 by a pin 51. The inner end of the spring 52 is,however, anchored to an intermediate plate 58 pivoted by a pin 59 on thefixed plate 54. An abutment 50 on the pivoted plate 58 underlies theplate 24 so that during its downward motion the plate 24 strikes theabutment 55 and swings the pivoted plate 55 in a direction to tensionthe spring 52. A second abutment 5| is provided on the plate 55,however, and is located in the path of a part l2 oi the descending slackdrawing hook l2 (Fig. 7). Consequently, when the latter approaches itslower extremity of movement it strikes the abutment 5| and swings theabutment 50 out of contact with the plate 24,

thereby interrupting the operative connection between the spring 52 andplate 24. Upon reference to the time chart (Fig. 13) it will be seenthat this extreme motion of the slack drawing hook l2 takes place at atime close to the end of the knotting operation and during which theslack drawing hook is pulling the thread a to draw the loops or the knottight and complete the same. By virtue of the arrangement described itwill be seen that only the single spring 5| acts on the plate 24 duringthis final tensioning operation so that the tensioning force exerted onthe reserve thread a is substantially diminished as compared to that inthe initial knot tying operation during which both of the springs 5| and52 act simultaneously to tension the reserve thread. The amount oftension provided for drawing the knot tight may be adjusted with nicetyby changing the setting or the spring 5| so as to conform with thetensile characteristics of the particular type 01' thread or yarn beingknotted.

In summary of the knotting operation, it will be seen that in generalthe threads are arranged as shown in Fig. 1* and then drawn tight to thefinal knotted arrangement of Fig. 1. In this final operation the twistedportion (14 of the thread a. is pulled within and squeezed by the mainloop in in the thread b. In this way a doubly interlocked knot ofextreme strength is formed. Preferably the threads are preliminarilyarranged (in the configuration of Fig. 1*) for this important final stepdescribed above, by first forming a doubly twisted main loop a: in onethread a (Fig. 8), completing a temporary bowknot by drawing a bow orloop as through the main loop (Fig. 11)

inserting a second thread I) through the bow as (Fig. 11), and thentensioning the running strand a: of the bow so as to dissolve the bowand withdraw the thread b through the main loop or (Fig. 12). Thecontinuation of tension in the strand a2, and withdrawal of the knotterpost 30, achieves the final transformation step in which the threadsshift position from that of Fig. 12 to that of Fig. 1, through theintermediate stages shown in Figs. 1' and 1. In the completed knot (Fig.1), the portion at of the thread a is encircled and squeezed by the loopin to accomplish an extra interlock between the threads in addition tothe interlocking loops and strands of an ordinary weavers knot. Byvirtue of this added interlock, a doubly interlocked knot is achievedwhich eiiectually unites even such springy material as wool strands.

Although a particular embodiment of the invention has been shown anddescribed in some detail, there is no intention to thereby limit theinvention to such embodiment and application, but on the other hand, theappended claims are intended to cover all other modifications within thespirit and scope of theinvention.

I claim as my invention:

1. The method of knotting together a pair of threads, which comprises,looping the threads together in the form or a loose weavers knot ofconventional configuration for such a knot except that the end or onethread, which normally in a standard weavers knot projects between aportion of the same thread and the strands of a loop formed in the otherthread, is instead twisted about said portion of the same thread andprojects free of said other thread; and then drawing the knot tight andas an incident to such tightening drawing said twisted portion of saidone thread through the loop in said other thread so that it is encircledand gripped by such loop.

resembles a loose single bowknot in one of the threads but in which knotthe strands at the base of the main loop, through which the bowprojects, are twisted about each other through substantially a full turnand a halt; inserting a second thread through the bow; tensioning therunning strand of the bow to withdraw the bow through said main loopalong with the second thread, which is inserted through it; andcontinuing the tensioning of such running strand until the final knot isdrawn tight with the twisted strands at the base oi the main loopencircled by a loop in the second thread.

3. The method of knotting together a pair oi threads which includes thepreliminary looping together of the threads in a modified form 01'weavers knot by first forming what generally resembles a loose singlebowknot in one of the threads but in which knot the strands at the baseor the main loop. h ough which the bow projects, are twisted about eachother through substantially a full turn and a half: then insertlng asecond thread through the bow; and tensioning the running strand of thebow to dissolve the bow and draw the second thread through said mainloop with the second thread itself looped about one of the strands ofsuch main loop.

4. A method of knotting together two threads in which, the threadsarepreliminarily arranged with oppositely projecting loops formed in therespective ends 01' the threads and with the standing part of one threadextending through the loop in the other thread while the end of said onethread is twisted about said standing part and projects freely of. saidlast named loop. and with both the standing part and one end of saidother thread projecting through the loop in said one thread, and thendrawing the knot tight after such preliminary configuration of thethreads and in such latter operation pulling said twisted portion ofsaid one thread through the loop in said other thread.

5. The method of knotting together a pair of threads which comprises,forming a main loop in one thread with the strands constituting the looptwisted through substantially a turn and a half at the base of the loop,then forming a second loop in a standing part of the thread adjacent themain loop and drawing it through the main loop from the side of thelatter opposite said standing part in which said second loop is formed,inserting a second thread through the second loop thus formed,withdrawing the second loop together with the inserted second thread.

whereby to dissolve said second loop and to form a third loop in saidsecond thread encircling one of the standing parts of the first thread,and applying a tensioning force to said last named standing part of saidfirst thread to draw said twisted base portion of said main loop throughsaid third loop as an incident to the final tightening of the knot. I

6. The method of knotting together a pair of threads, which comprises,forming a main loop in one thread with the strands constituting the looptwisted through substantially a turn and a half at the base of the loop,then forming a second loop in a standing part of the thread adjacent themain loop and drawing it through the main loop from the side of thelatter opposite said standing part in which said second loop is formed,inserting a second thread through the means for intertwining a pairsecond loop thus formed, and withdrawing the second loop together withthe inserted second thread, whereby to dissolve said second loop and toform a third loop in said second thread encircling one of thestandingparts oi the first thread.

7. A knotter comprising, in combination, means for forming a loosesingle bowknot in a first thread but with the strands of the main looptwisted through substantially a full turn and a half, means forinserting a second thread through the bow or the knot formed by saidfirst named means, and means for tensioning the running strand of thebow to withdraw the bow through the main loop of the bowknot along withthe second thread inserted through it and finally to pull the twistedbase portion of the main loop within the resulting loop in the secondthread as an incident to drawing tight the completed knot.

8. A knotter comprising; in combination, means for forming a loosesingle bowknot in a first thread but with the strands of the main looptwisted through substantially a full turn and a half, means'torinserting a second thread through the bow of the knot formed by thefirst named means, and -means for tensioning the running strand of thebow to dissolve the bow and draw the second thread through the main loopwith the second thread itself looped about one of the strands 01 suchmain loop.

9. A knotter comprising, in combination, means including a rotatablehook engageable with a bight in a first thread for'forming a loop insuch thread with the strands at the base of the loop twistedthrough'substantially a first turn and a half, means for positioning oneof the twisted strands for engagement by the hook to form a second loopin said one thread extending through the first loop, means for insertinga second thread through the second loop, and means for tensioning one ofthe strands of the first thread to draw the twisted base portion of thefirst loop within a loop formed in the second thread as an incident tothe withdrawal of the second thread and the second loop through thefirst loop.

10. A knotter comprising, in combination, means for looping a threadwith the strands of the loop twisted about themselves and for drawingone of the strands through the loop in the manner of a bow in a bowknot,means for inserting a second thread through the bow, and means fortensioning the running strand of the bow to dissolve the latter and topull the second thread into a loop interlocked with a strand of the mainloop and finally to draw the twisted portion of the first thread withinthe loop in the second thread as an incident to completion of thetightening of the knot.

11. A knotter comprising, in combination, means for intertwining a pairof threads in the form 01' a knot, means for tensioning at least one ofsaid threads during a plurality of periods in the knotting operation ofsaid first named means, and means operable in timed relation to thefirst named means for varying the tensioning i'orce produced by thesecond named means.

12. A knotter comprising, in combination, of threads in the form or aknot, means including a pair oi. relatively movable tensioning membersadapted to receive at least one oi the threads therebetween to tensionthe same by relative movement between said members,

means including apair of yieldable resilient members for resistingmovement of one of said tensioning members, and means responsive to apredetermined relative movement between said tensioning members forrendering at least one of said resilient members ineflective thereafterto resist movement of said one tensioning member.

13. A knotter comprising, in combination, means for intertwining a pairof threads in the form of a knot, a pivoted plate arranged to have atleast one of the threads led over an edge thereof, a hook at one side ofsaid plate disposed to move past the adjacent plate face to tension suchthread by pulling it across said plate edge, said plate being movableabout its pivot in the direction of hook movement, means including aplurality of springs for yieldably biasing said plate to swing about itspivot in a direction to tension the thread, and means responsive to apredetermined movement of said hook in one direction for rendering atleast one of said springs ineifective to bias said plate during furthermovement of said hook in said one direction.

14. A knotter comprising, in combination, means for intertwining a pairof threads in the form of a knot, a pivoted plate arranged to have atleast one of the threads led over an edge thereof, a hook at one side ofsaid plate disposed to move past the adjacent plate face to tension suchthread by pulling it across said plate edge, said plate being movableabout its pivot in the direction of hook movement, means including apair of springs for yieldably biasing said plate to swing about itspivot in a direction to tension the thread, means responsive to apredetermined movement of said hook in one direction for rendering oneof said springs ineffective to bias said plate during further movementof said hook in said one direction, and means for adjusting the torqueapplied to said plate by the other spring.

15. A knotter comprising, in combination, means for intertwining a pairof threads in the form of a knot, a pivoted plate arranged to have atleast one of the threads led over an edge thereof, a hook at one side ofsaid plate disposed to move past the adjacent plate face to tension suchthread by pulling it across said plate edge, said plate being movableabout its pivot in the direction of hook movement, a spring foryieldably biasing said plate to swing about its pivot in a direction totension the thread, a second member pivoted for movement about an axiscoincident with that of said plate, said plate and second member beingfashioned with portions engageable upon movement of said plate in adirection to relieve the tension in the thread, a second spring forbiasing said second member for movement in a direction to causeengagement of it with said plate and toswing the latter to tension thethread, and means including interengaging portions of said hook andsecond member for causing the hook to move said second member out ofengagement with said plate after a predetermined movement of said hookin a thread tensioning direction.

16. In a knotter mechanism embodying a laterally shiftable knotter postand a movable slack drawing member, the combination of a thread clampcomprising a pair of relatively movable clamping jaws, and meansresponsive to movement of the slack drawing member for shifting saidjaws relatively to each other from a full open position to anintermediate although still open position, said last named means beingresponsive to a lateral shift of the knotter post for closing said jawsfrom such intermediate position.

17. In a knotter mechanism embodying a laterally shiftable knotter postand a movable slack drawing member, the combination of a thread clampcomprising a pair of relatively movable clamping jaws, and meansresponsive to the movement of the slack drawing member for shifting saidjaws relatively to each other from a full open position to anintermediate although still open position, said last named means beingresponsive to an initial lateral shift of the knotter post in onedirection for closing said jaws i'rom such intermediate position andresponsive to a further shift of the knotter post in the same directionfor reopening said jaws.

18. In a knotter mechanism the combination with a movable knottingdevice engageable with a thread to be tied, of a thread clamp comprisinga pair of relatively movable clamping jaws, and means responsive to amovement of said device in one direction for closing said jaws andresponsive to a further predetermined movement of said device in thesame direction for reopening said jaws. 1 a

19. In a knotter mechanism the combination with a movable knottingdevice engageable with a thread to be tied, of a thread clamp comprisinga pair of relatively movable jaws, means responsive to a movement ofsaid device in one direction for closing said jaws and responsive to afurther predetermined movement of said device in the same direction forreopening said jaws, and means for retaining said jaws'in, theirreopened position during a return of said device to its initialposition.

20. In a knotter mechanism the combination of, a laterally shiftablelever having a knotter post mounted thereon, a movable slack drawingdevice, an actuator arm for saiddevice, a fixed thread clamping jaw anda cooperating pivoted jaw having a slot therein, a pin in said slot,means on said actuator arm for camming said pin in a direction to pivotsaid movable jaw toward closed position in response to movement of saidactuator arm, and means including a link pivoted at one, end on saidlever and carryingsaid pin on the other end for pivoting said movablejaw still tur ther and into fully closed position in response to alateral shift of said lever carrying said knotterpost.

HARRY G. LIND.

